#o在字符串中出现的次数
from collections import Counter
import math
s='hello world'
l=Counter(s)
print(l['o'])

#排序
a=[1,4,2,6,3,8,1]
a=sorted(a)
print(a)
print(a[::-1])


#居中对齐
print("{:*^20}".format('hello'))

# map(int,input().split())

import math
print(math.gcd(4,6))#最大公因数
def lcm(a,b):#最小公倍数
    return abs(a*b)//math.gcd(a,b)
print(lcm(2,5))